Device for continuously forming a multiply tube



Sept. 1, 1964 J. BOONE 3,146,685

DEVICE FOR CONTINUOUSLY FORMING A MULTIPLY TUBE Filed Nov. 15, 1960 3 Sheets-Sheet l INVENTOR JOSEPH BOONE r BY ATTORN YS J. BOONE Sept. 1, 1964 I DEVICE FOR CONTINUOUSLY FORMING A MULTIPLY TUBE 3 Sheets-Sheet 2 Filed Nov. 15, 196 0 I NVE TO B NE JOSEPH DEVICE FOR CONTINUOUSLY FORMING A MULTIPLY TUBE Filed Nov. 15, 1960 J. BOONE Sept. 1, 1964 3 Sheets-Sheet 3 I NVENTOR JOSEPH BOONE I n a M flaws.

United States Patent 3,146,685 DEVICE FOR CONTHNUOUSLY FORMING A MULTIPLY TUBE .loseph Boone, Vedrin, Belgium, assignor to Marius Berghgracht, Vineuil St. Firmin (Oise), France Filed Nov. 15, 12560, Ser. No. 69,425 Claims priority, application Belgium Nov. 17, 1959 Claims. (Cl. 93-8) The invention relates to forming a multiply tube usable for producing a bag, particularly a large capacity bag of the kind used for packing cement, chalk, animal food, etc. Bags of this type are made from a multiply length of tube which is closed at its ends, more particularly by means of a transverse stitch. The particular object of the invention is the manufacture of a multiply tube usable for producing a bag of the aforesaid type, which will be impervious and will also be suitable for packing liquid and pasty materials which have normally to be packed in metal or wood barrels, or the like.

According to the invention, the tube, which includes a number of paper or like plies, is provided with an innermost ply from thermosealable, impervious material, for instance from thermosealable or thermoweldable sheet material, such as polyethylene, or from paper treated with plastic materials, crepe paper, or the like, which shows an absolute length which is greater than its apparent length, the latter being substantially equal to that of the outer plies. Owing to this arrangement, the pressure exerted by the contents of the bag, whose weight is, for instance, of the order of 50 kg. (110 lbs.) or even more, is not likely to burst the said seals of the inner ply open, which would impair the imperviousness of the bag.

The invention provides a device for continuously forming a multiply tube including an innermost, impervious ply having an absolute length greater than the length of the outer plies. The device includes any suitable, known means for converting a web into a flat tube by bonding the longitudinal edges thereof to each other and for wrapping the said innermost tube in one or more outer tubes formed in a similar Way. According to the invention,- the innermost webwhich is folded in order to form a tube is acted upon by a first group of driving members, more particularly rollers mounted on a shaft arranged transversely with respect to the tube, and a second group of similar driving members, mounted downstream and imparting to the tube a speed of forward movemnt which is slightly smaller than the speed of forward movement imparted thereto by the first group and is equal to that imparted to the tubes which are to be subsequently formed about the inermost tube and to constitute the outer plies, means being provided and adapted to cooperate with the said groups, for sealing or welding the longitudinal seam of the inner most tube and for subsequently setting the latter seam to an apparent length which is smaller than the absolute length of the innermost ply and is equal to that of the outer plies.

To manfaucture large capacity bags from a multiply tube produced according to the invention, the multiply tube, which is formed as specified above, is severed into sections of suitable length. In order to avoid the risk of the transverse seams of the inner ply bursting open under the action of the contents of the bag, provision may be made for the ratio between the absolute length and the apparent length of the innermost ply to be, for instance, at least 52:50.

Further features and advantages of the invention will appear from the disclosure of one embodiment of the invention, which will be given hereinafter by way of example with reference to the accompanying diagrammatical drawings, in which:

FIG. 1 is a side elevational view of a bag tubing ma- Patented Sept. 1, 1964 chine for forming a multiply tube according to the invention,

FIG. 2 is a part view, in plan, of the bag tubing machine, I

FIG. 3 is an enlarged, fragmentary perspective view of the bag tubing machine,

FIG. 4 is an enlarged cross sectional view showing one wlay of forming the longitudinal joint of the inner most P Y,

FIG. 5, whose two sections are supposed to be placed end to end along the line X-X, is a plan view showing a bag making machine,

FIGS. 6 and 7 are enlarged side elevation and perspective views, respectively, of a detail of the bag making machine,

FIG. 8 is an enlarged side view of a further detail of the machine,

FIG. 9 is a slightly enlarged sectional view taken along line 99 of FIG. 5,

FIG. 10 is a part view of a bag in the course of manufacture, and

FIG. 11 is a perspective view of a bag having different relative dimensions.

The bag tubing machine shown in FIGS. 1 and 2 provides for continuously forming a multiply tube including, for instance, four plies.

A web of polyethylene, or the like, indicated by 1, is fed over the roller 2, while three Webs of paper, or the like, numbered 3, are fed over the rollers 4. The web 1 is led on guide members 5 carried by a holder 6, not shown in FIG. 2, and is folded in the usual way along a folder rail, comprised of a straight blade, with the assistance of guide rails 7 and rollers lined with rubber, such as 8.

The web is thus folded fiat, so that its margins overlap one another. The web is subsequently sealed longitudinally in a manner that will be presently described.

The webs 3 are held in spaced relationship with respect to the web 1 by means of rollers 9, are pasted at 10 and led along the guide members 11, which are also carried by the holder 6, the webs 3 remaining spaced from the web 1 until the latter has been formed into a sealed tube. Thereupon, the webs 3 are folded by the action of guide rails 12 and of drive rollers 13 and pressure rollers 13'- about the tube 1, which is still engaging the folder rail. The outer plies 3 may be bonded to each other, both longitudinally and transversely. The longitudinal joint of the outer plies may lie on top of the longitudinal joint of the innermost ply 1 or laterally thereof. The multiply tube so provided is then severed into section of desired length by the cutting device 14, which is provided with means applying a pull on the tube, in order to impart a predetermined rate of feed to the latter.

The folded web 1 is subjected to preheating at 15, in the overlapping zone thereof. The web will then move under a first group of drive members, including one or more (two in the example illustrated) sets each comprising two drive rollers 16 mounted on a common shaft which also carries an intermediate roller 17 constituting a sealing roller, the latter roller being heated and exerting a pressure on the longitudinal joint of the web 1.

The number of sealing rollers depends, more particularly, on the nature of the web 1 and on the rate of feed. A second group of drive members is arranged downstream with respect of the first group and includes, mounted on a common shaft, two drive rollers 18 and an intermediate pressure roller 19. The second group, which may be cooled if desired, imparts to the web 1 a speed equal to that imparted to the tube 3, formed of the outer plies, but smaller than the speed imparted by the said first group to the tube 1, the ratio being not higher than about 50:52, for instance. Between the first and the second group, the longitudinal sealed joint of the web-and, consequently, the web itself, to a certain extentwill be subjected to a certain corrugation, shown with exaggerated amplitude in FIG. 1, and, as a result, a sort of accordion or gathering will be formed and rendered permanent under the second group, whereby the innermost tube 1 is given an apparent length which is smaller than the absolute length thereof, the two lengths being related to one another in the same ratio as the speeds, i.e. a ratio of about 50:52, for instance. Cooled pressure rollers 19 may further be provided.

As shown in FIGS. 3 and 4, the longitudinal sealing joint may be formed by folding and overlapping the margins of the web 1, so that both margins of the latter may be welded to one another by their inner faces. This procedure is particularly suitable in those instances where the web 1 has merely one of its faces covered with a thermosealable coating or lac. Where the web is of thermosealable material, the sealing may be performed by merely overlapping the margins.

FIG. 3 shows a tube folded so as to exhibit bellows or gussets 21, but it will be understood that the tube could be just as well folded flat. When it is desired to manufacture a bag whose innermost ply has a slightly larger perimeter than that of the innermost ply but one, in order to avoid any pull on the longitudinal joint of the innermost ply once the bag has been filled, the latter ply may be formed With deeper gussets. Alternately, the guides 5 may be given a greater width and that portion of the folder rail about which the web 1 is being folded may be made of greater width than the portion thereof about which the outer plies 3 are folded over the ply l.

FIGS. 5 to 9 show a bag making machine, the bag in this instance being a valve bag. The multiply tube sections, such as severed at 14, are fed at 22 and caught by drawing conveyors 23, the open ends of the tube sections being situated outside the drawing conveyors. One of the open ends of the innermost ply 1 is thermosealed by means of heating rollers 24, which preferably effect two spaced welds, between which it will be possible to stitch together the whole of the plies of the bag. At the same time takes place the welding of the other end of the bag, which latter end is provided with a valve 25 (FIGS. 10, 11) formed by folding one corner of the bag inwardly. A sleeve 26, of thermosealable or thermoweldable material is inserted into the valve opening mechanically or by hand, the edge of the sleeve being situated practically at the end of the bag.

The inner end portion of the sleeve is folded, at 27, about the valve 25. The sleeve has been, of course, positioned before the corresponding end of the bag has been welded. The corresponding end of the inner ply 1 is welded by heating rollers 28, similar to the rollers 24. The second roller 28 bears a heating strip 29, at right angles to the plane of the roller, which strip effects the weld securing the sleeve 26, at 27, to the inner ply 1, the circumference of the roller being equal to the width of the bag.

The sewing devices 30 would then make, at 31, the stitches by which the whole of the plies of the bag are assembled at both ends of the latter the stitches being laid, for instance, between the two welds provided at either end of the innermost ply. Thus, the stitch also comes to lie in the upper edge portion of the sleeve.

A reinforcement member 32, formed by a U-shaped strip embracing the end margain of the bag, is secured, for instance by an adhesive, onto each end of the bag, thus concealing the cord of the stitches 31. The ends of the reinforcement member which extend beyond the edges of the bag are cut off at 33.

Guide members 34 and 35 cause the ends of the bag to be bent downwardly, the bag being caught by the conveyor belts as. The downwardly bent ends are dipped into channels 37 filled with molten parafiine, in order to still improve the tightness. The bag will then be caught by the belts 38, which will lift the latter slightly, so as to disengage the ends thereof from channels 37 and to let the paraffine drip into channels 39. The bag is finally delivered at 40.

It will be understood that the invention is not restricted to the example described and illustrated, which may undergo various changes without departing from the spirit of the said invention.

What I claim is:

1. A device, for continuously forming an elongated multiply tube usable for producing a bag, comprising an elongated folder rail, means for folding a web around said folder rail into a flat tube to form the inner ply of the multiply tube, means for moving the so formed inner tube along said folder rail and including a first group of driving members formed by rollers mounted on a shaft arranged transversely with respect to said folder rail and a second group of similar driving members mounted downstream which impart to the inner tube a speed of forward movement along said rail which is slightly smaller than the speed of forward movement imparted thereto by the said first group and is equal to the speed imparted to the tubes which are to be formed subsequently about the innermost tube and to constitute the outer plies, the difference in speed of said first and second groups of driving members being effective to automatically gather the inner tube on said folder rail in a continuous series of transverse corrugations between said two groups of driving members, means cooperating with the said first group for adhering together the edges forming the longitudinal joint of the innermost tube, means cooperating with said second group for rendering permanent said corrugations in a peripheral zone of the inner tube including said joint and thereby setting the latter joint to an apparent length which is smaller than the absolute length of the innermost ply and is equal to that of the outer plies, and means for then folding the outer plies around the so formed inner tube and closing them longitudinally.

2. A device as claimed in claim 1 wherein the ratio between the rate of feed imparted by the first group and the one imparted by the second group is not smaller than about 52/50.

3. A device, for continuously forming a multiply tube usable for producing a bag, comprising an elongated folder rail, means for folding a web around said folder rail and converting it into a flat tube to form the inner ply of the multiply tube, means for moving the so formed inner tube along said folder rail, and means for folding a web of at least one outer ply as a flat tube around said inner tube, said means for moving the inner tube including a first group of driving members disposed adjacent said rail and a second group of similar driving members mounted downstream and adjacent the rail which impart to the inner tube a speed of forward movement which is slightly smaller than the speed of forward movement imparted thereto by the said first group and is equal to the speed imparted to the tube which is to be formed subsequently about the innermost tube and to constitute the outer ply, means for setting a longitudinal portion of the inner tube, located between said two groups of driving members, on a portion of the periphery of said tube, to an apparent length corresponding to the distance between said two groups, which apparent length is smaller than the absolute length of the innermost ply and is equal to that of the outer ply, and means for then folding the outer ply around the so formed inner tube and closing it longitudinally.

4. A device as claimed in claim 3 wherein the ratio between the rate of feed imparted by the first group and the one imparted by the second group is not smaller than about 52/50.

5. A device for continuously forming a multiply tube usable for producing a bag and including an inner ply formed by a flat tube and at least one outer ply formed 5 from a web and folded as a flat tube around said inner tube, comprising a flat, elongated support, means for moving the inner tube along said support while surrounding the latter, said means including a first group of driving members and a second group of similar driving members mounted downstream which impart to the inner tube a speed of forward movement which is slightly smaller than the speed of forward movement imparted thereto by the said first group and is equal to the speed imparted to the tube which is to be formed subsequently about the innermost tube and to constitute the outer ply, the diflference in speed of said first and second groups of driving members being effective to gather the inner tube on said support in a continuous series of transverse corrugations between said two groups of driving members, means extending over a portion of the periphery of the inner flat tube for rendering permanent the said corrugations in the said portion and thereby to set said longitudi nal portion of the inner tube so an apparent length which is smaller than the absolute length of the innermost ply and is equal to that of the outer ply, and means for then folding said at least one outer ply around the so formed inner tube and closing it in the form of a flat tube.

References Cited in the file of this patent UNITED STATES PATENTS 2,125,758 Waters Aug. 2, 1938 2,180,431 Robinson Nov. 21, 1939 2,256,506 Wagner Sept. 23, 1941 2,305,470 Gibbs Dec. 15, 1942 2,437,693 Hartman Mar. 16, 1948 2,803,173 Doyle Aug. 20, 1957 2,818,003 Browning et al. Dec. 31, 1957 2,842,032 Mossor' July 8, 1958 2,855,136 Clay Oct. 7, 1958 2,865,556 Williams Dec. 23, 1958 

1. A DEVICE, FOR CONTINUOUSLY FORMING AN ELONGATED MULTIPLY TUBE USABLE FOR PRODUCING A BAG, COMPRISING AN ELONGATED FOLDER RAIL, MEANS FOR FOLDING A WEB AROUND SAID FOLDER RAIL INTO A FLAT TUBE TO FORM THE INNER PLY OF THE MULTIPLY TUBE, MEANS FOR MOVING THE SO FORMED INNER TUBE ALONG SAID FOLDER RAIL AND INCLUDING A FIRST GROUP OF DRIVING MEMBERS FORMED BY ROLLERS MOUNTED ON A SHAFT ARRANGED TRANSVERSELY WITH RESPECT TO SAID FOLDER RAIL AND A SECOND GROUP OF SIMILAR DRIVING MEMBERS MOUNTED DOWNSTREAM WHICH IMPART TO THE INNER TUBE A SPEED OF FORWARD MOVEMENT ALONG SAID RAIL WHICH IS SLIGHTLY SMALLER THAN THE SPEED OF FORWARD MOVEMENT IMPARTED THERETO BY THE SAID FIRST GROUP AND IS EQUAL TO THE SPEED IMPARTED TO THE TUBES WHICH ARE TO BE FORMED SUBSEQUENTLY ABOUT THE INNERMOST TUBE AND TO CONSTITUTE THE OUTER PLIES, THE DIFFERENCE IN SPEED OF SAID FIRST AND 